[PATCH] media: aspeed: Fix the NULL vs IS_ERR() bug for debugfs_create_file()

[Hans Verkuil]

On 14/09/2023 05:31, Jinjie Ruan wrote:
> Since debugfs_create_file() returns ERR_PTR and never NULL, use IS_ERR() to
> check the return value.
> 
> And so return the err code based on IS_ERR instead of checking NULL.
> 
> Fixes: 52fed10ad756 ("media: aspeed: add debugfs")
> Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
> ---
>  drivers/media/platform/aspeed/aspeed-video.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/aspeed/aspeed-video.c b/drivers/media/platform/aspeed/aspeed-video.c
> index a9c2c69b2ed9..f4e624c13d3b 100644
> --- a/drivers/media/platform/aspeed/aspeed-video.c
> +++ b/drivers/media/platform/aspeed/aspeed-video.c
> @@ -1975,10 +1975,12 @@ static int aspeed_video_debugfs_create(struct aspeed_video *video)
>  	debugfs_entry = debugfs_create_file(DEVICE_NAME, 0444, NULL,
>  					    video,
>  					    &aspeed_video_debugfs_fops);
> -	if (!debugfs_entry)
> +	if (IS_ERR(debugfs_entry)) {
>  		aspeed_video_debugfs_remove(video);
> +		return -EIO;
> +	}
>  
> -	return !debugfs_entry ? -EIO : 0;
> +	return 0;
>  }
>  #else
>  static void aspeed_video_debugfs_remove(struct aspeed_video *video) { }

Actually, standard behavior is not to check the error at all. It is not
considered a bug if creating a debugfs directory fails, you can just continue.

So rather than 'fixing' this, just drop the error check completely.

See e.g. commit 8c23f411296e ("media: sti: no need to check return value of
debugfs_create functions").

Regards,

	Hans